Clinical examination and diagnosis of disease are carried out by detecting disease-related genes and proteins contained in biological samples using methods such as gene detection, immunological detection and the like. Electrochemical detection methods for sample substances are known as methods for clinical examination and diagnosis. Specifically, methods used for the detection of sample substances such as genes and proteins have been proposed which use electrical current generated by photoexcitation of a photochemically active labeled material, and current generated by photoexcitation or light generated by a voltage applied to an electrochemically active labeled substance.
When detecting a sample substance within a sample for clinical examination and diagnosis, the minute amount of sample substance within the sample must be detected with high sensitivity. For example, U.S. Patent Publication No. 2006/078912 discloses a method of detecting a sample substance using carrier particles which have a probe that binds to the sample substance and a plurality of electrochemically active ECL. When detecting electrochemiluminescence (ECL), the carrier is dissolved and dispersed by ECL release. Hence, contact efficiency between ECL and electrolyte is improved, which improves detection sensitivity. Therefore, development of a method of electrochemical detection capable of detecting a sample substance with higher sensitivity is desirable.